<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Page.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Cache_Core
 */
require_once 'Zend/Cache/Core.php';

/**
 * @package    Zend_Cache
 * @subpackage Zend_Cache_Frontend
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Cache_Frontend_Page extends Zend_Cache_Core {
	/**
	 * This frontend specific options
	 *
	 * ====> (boolean) http_conditional :
	 * - if true, http conditional mode is on
	 * WARNING : http_conditional OPTION IS NOT IMPLEMENTED FOR THE MOMENT (TODO)
	 *
	 * ====> (boolean) debug_header :
	 * - if true, a debug text is added before each cached pages
	 *
	 * ====> (boolean) content_type_memorization :
	 * - deprecated => use memorize_headers instead
	 * - if the Content-Type header is sent after the cache was started, the
	 * corresponding value can be memorized and replayed when the cache is hit
	 * (if false (default), the frontend doesn't take care of Content-Type header)
	 *
	 * ====> (array) memorize_headers :
	 * - an array of strings corresponding to some HTTP headers name. Listed headers
	 * will be stored with cache datas and "replayed" when the cache is hit
	 *
	 * ====> (array) default_options :
	 * - an associative array of default options :
	 * - (boolean) cache : cache is on by default if true
	 * - (boolean) cacheWithXXXVariables  (XXXX = 'Get', 'Post', 'Session', 'Files' or 'Cookie') :
	 * if true,  cache is still on even if there are some variables in this superglobal array
	 * if false, cache is off if there are some variables in this superglobal array
	 * - (boolean) makeIdWithXXXVariables (XXXX = 'Get', 'Post', 'Session', 'Files' or 'Cookie') :
	 * if true, we have to use the content of this superglobal array to make a cache id
	 * if false, the cache id won't be dependent of the content of this superglobal array
	 * - (int) specific_lifetime : cache specific lifetime
	 * (false => global lifetime is used, null => infinite lifetime,
	 * integer => this lifetime is used), this "lifetime" is probably only
	 * usefull when used with "regexps" array
	 * - (array) tags : array of tags (strings)
	 * - (int) priority : integer between 0 (very low priority) and 10 (maximum priority) used by
	 * some particular backends
	 *
	 * ====> (array) regexps :
	 * - an associative array to set options only for some REQUEST_URI
	 * - keys are (pcre) regexps
	 * - values are associative array with specific options to set if the regexp matchs on $_SERVER['REQUEST_URI']
	 * (see default_options for the list of available options)
	 * - if several regexps match the $_SERVER['REQUEST_URI'], only the last one will be used
	 *
	 * @var array options
	 */
	protected $_specificOptions = array ('http_conditional' => false, 'debug_header' => false, 'content_type_memorization' => false, 'memorize_headers' => array (), 'default_options' => array ('cache_with_get_variables' => false, 'cache_with_post_variables' => false, 'cache_with_session_variables' => false, 'cache_with_files_variables' => false, 'cache_with_cookie_variables' => false, 'make_id_with_get_variables' => true, 'make_id_with_post_variables' => true, 'make_id_with_session_variables' => true, 'make_id_with_files_variables' => true, 'make_id_with_cookie_variables' => true, 'cache' => true, 'specific_lifetime' => false, 'tags' => array (), 'priority' => null ), 'regexps' => array () );
	
	/**
	 * Internal array to store some options
	 *
	 * @var array associative array of options
	 */
	protected $_activeOptions = array ();
	
	/**
	 * If true, the page won't be cached
	 *
	 * @var boolean
	 */
	protected $_cancel = false;
	
	/**
	 * Constructor
	 *
	 * @param  array   $options                Associative array of options
	 * @param  boolean $doNotTestCacheValidity If set to true, the cache validity won't be tested
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	public function __construct(array $options = array()) {
		while ( list ( $name, $value ) = each ( $options ) ) {
			$name = strtolower ( $name );
			switch ($name) {
				case 'regexps' :
					$this->_setRegexps ( $value );
					break;
				case 'default_options' :
					$this->_setDefaultOptions ( $value );
					break;
				case 'content_type_memorization' :
					$this->_setContentTypeMemorization ( $value );
					break;
				default :
					$this->setOption ( $name, $value );
			}
		}
		if (isset ( $this->_specificOptions ['http_conditional'] )) {
			if ($this->_specificOptions ['http_conditional']) {
				Zend_Cache::throwException ( 'http_conditional is not implemented for the moment !' );
			}
		}
		$this->setOption ( 'automatic_serialization', true );
	}
	
	/**
	 * Specific setter for the 'default_options' option (with some additional tests)
	 *
	 * @param  array $options Associative array
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	protected function _setDefaultOptions($options) {
		if (! is_array ( $options )) {
			Zend_Cache::throwException ( 'default_options must be an array !' );
		}
		foreach ( $options as $key => $value ) {
			if (! is_string ( $key )) {
				Zend_Cache::throwException ( "invalid option [$key] !" );
			}
			$key = strtolower ( $key );
			if (isset ( $this->_specificOptions ['default_options'] [$key] )) {
				$this->_specificOptions ['default_options'] [$key] = $value;
			}
		}
	}
	
	/**
	 * Set the deprecated contentTypeMemorization option
	 *
	 * @param boolean $value value
	 * @return void
	 * @deprecated
	 */
	protected function _setContentTypeMemorization($value) {
		$found = null;
		foreach ( $this->_specificOptions ['memorize_headers'] as $key => $value ) {
			if (strtolower ( $value ) == 'content-type') {
				$found = $key;
			}
		}
		if ($value) {
			if (! $found) {
				$this->_specificOptions ['memorize_headers'] [] = 'Content-Type';
			}
		} else {
			if ($found) {
				unset ( $this->_specificOptions ['memorize_headers'] [$found] );
			}
		}
	}
	
	/**
	 * Specific setter for the 'regexps' option (with some additional tests)
	 *
	 * @param  array $options Associative array
	 * @throws Zend_Cache_Exception
	 * @return void
	 */
	protected function _setRegexps($regexps) {
		if (! is_array ( $regexps )) {
			Zend_Cache::throwException ( 'regexps option must be an array !' );
		}
		foreach ( $regexps as $regexp => $conf ) {
			if (! is_array ( $conf )) {
				Zend_Cache::throwException ( 'regexps option must be an array of arrays !' );
			}
			$validKeys = array_keys ( $this->_specificOptions ['default_options'] );
			foreach ( $conf as $key => $value ) {
				if (! is_string ( $key )) {
					Zend_Cache::throwException ( "unknown option [$key] !" );
				}
				$key = strtolower ( $key );
				if (! in_array ( $key, $validKeys )) {
					unset ( $regexps [$regexp] [$key] );
				}
			}
		}
		$this->setOption ( 'regexps', $regexps );
	}
	
	/**
	 * Start the cache
	 *
	 * @param  string  $id       (optional) A cache id (if you set a value here, maybe you have to use Output frontend instead)
	 * @param  boolean $doNotDie For unit testing only !
	 * @return boolean True if the cache is hit (false else)
	 */
	public function start($id = false, $doNotDie = false) {
		$this->_cancel = false;
		$lastMatchingRegexp = null;
		if (isset ( $_SERVER ['REQUEST_URI'] )) {
			foreach ( $this->_specificOptions ['regexps'] as $regexp => $conf ) {
				if (preg_match ( "`$regexp`", $_SERVER ['REQUEST_URI'] )) {
					$lastMatchingRegexp = $regexp;
				}
			}
		}
		$this->_activeOptions = $this->_specificOptions ['default_options'];
		if ($lastMatchingRegexp !== null) {
			$conf = $this->_specificOptions ['regexps'] [$lastMatchingRegexp];
			foreach ( $conf as $key => $value ) {
				$this->_activeOptions [$key] = $value;
			}
		}
		if (! ($this->_activeOptions ['cache'])) {
			return false;
		}
		if (! $id) {
			$id = $this->_makeId ();
			if (! $id) {
				return false;
			}
		}
		$array = $this->load ( $id );
		if ($array !== false) {
			$data = $array ['data'];
			$headers = $array ['headers'];
			if (! headers_sent ()) {
				foreach ( $headers as $key => $headerCouple ) {
					$name = $headerCouple [0];
					$value = $headerCouple [1];
					header ( "$name: $value" );
				}
			}
			if ($this->_specificOptions ['debug_header']) {
				echo 'DEBUG HEADER : This is a cached page !';
			}
			echo $data;
			if ($doNotDie) {
				return true;
			}
			die ();
		}
		ob_start ( array ($this, '_flush' ) );
		ob_implicit_flush ( false );
		return false;
	}
	
	/**
	 * Cancel the current caching process
	 */
	public function cancel() {
		$this->_cancel = true;
	}
	
	/**
	 * callback for output buffering
	 * (shouldn't really be called manually)
	 *
	 * @param  string $data Buffered output
	 * @return string Data to send to browser
	 */
	public function _flush($data) {
		if ($this->_cancel) {
			return $data;
		}
		$contentType = null;
		$storedHeaders = array ();
		$headersList = headers_list ();
		foreach ( $this->_specificOptions ['memorize_headers'] as $key => $headerName ) {
			foreach ( $headersList as $headerSent ) {
				$tmp = explode ( ':', $headerSent );
				$headerSentName = trim ( array_shift ( $tmp ) );
				if (strtolower ( $headerName ) == strtolower ( $headerSentName )) {
					$headerSentValue = trim ( implode ( ':', $tmp ) );
					$storedHeaders [] = array ($headerSentName, $headerSentValue );
				}
			}
		}
		$array = array ('data' => $data, 'headers' => $storedHeaders );
		$this->save ( $array, null, $this->_activeOptions ['tags'], $this->_activeOptions ['specific_lifetime'], $this->_activeOptions ['priority'] );
		return $data;
	}
	
	/**
	 * Make an id depending on REQUEST_URI and superglobal arrays (depending on options)
	 *
	 * @return mixed|false a cache id (string), false if the cache should have not to be used
	 */
	protected function _makeId() {
		$tmp = $_SERVER ['REQUEST_URI'];
		$array = explode ( '?', $tmp, 2 );
		$tmp = $array [0];
		foreach ( array ('Get', 'Post', 'Session', 'Files', 'Cookie' ) as $arrayName ) {
			$tmp2 = $this->_makePartialId ( $arrayName, $this->_activeOptions ['cache_with_' . strtolower ( $arrayName ) . '_variables'], $this->_activeOptions ['make_id_with_' . strtolower ( $arrayName ) . '_variables'] );
			if ($tmp2 === false) {
				return false;
			}
			$tmp = $tmp . $tmp2;
		}
		return md5 ( $tmp );
	}
	
	/**
	 * Make a partial id depending on options
	 *
	 * @param  string $arrayName Superglobal array name
	 * @param  bool   $bool1     If true, cache is still on even if there are some variables in the superglobal array
	 * @param  bool   $bool2     If true, we have to use the content of the superglobal array to make a partial id
	 * @return mixed|false Partial id (string) or false if the cache should have not to be used
	 */
	protected function _makePartialId($arrayName, $bool1, $bool2) {
		switch ($arrayName) {
			case 'Get' :
				$var = $_GET;
				break;
			case 'Post' :
				$var = $_POST;
				break;
			case 'Session' :
				if (isset ( $_SESSION )) {
					$var = $_SESSION;
				} else {
					$var = null;
				}
				break;
			case 'Cookie' :
				if (isset ( $_COOKIE )) {
					$var = $_COOKIE;
				} else {
					$var = null;
				}
				break;
			case 'Files' :
				$var = $_FILES;
				break;
			default :
				return false;
		}
		if ($bool1) {
			if ($bool2) {
				return serialize ( $var );
			}
			return '';
		}
		if (count ( $var ) > 0) {
			return false;
		}
		return '';
	}

}
